The present invention relates to a hydrocarbon conversion process and a catalyst composition utilized in said hydrocarbon conversion process. More particularly, the invention relates to an improved alkylation process for the production of an alkylate product by contacting hydrocarbons with a novel composition.
The use of catalytic alkylation processes to produce branched hydrocarbons having properties that are suitable for use as gasoline blending components is well known in the art. Generally, the alkylation of olefins by saturated hydrocarbons, such as isoparaffins, is accomplished by contacting the reactants with an acid catalyst to form a reaction mixture, settling said mixture to separate the catalyst from the hydrocarbons, and further separating the hydrocarbons, for example, by fractionation, to recover the alkylation reaction product. Normally, the alkylation reaction product is referred to as “alkylate”, and preferably contains hydrocarbons having to 7-9 carbon atoms. In order to have the highest quality gasoline blending stock, it is preferred that hydrocarbons formed in the alkylation process be highly branched.
One of the more desirable alkylation catalysts is hydrofluoric acid (HF), however, the use of hydrofluoric acid as an alkylation catalyst has certain drawbacks. One problem with the use of hydrofluoric acid as an alkylation catalyst is that it is corrosive and it is toxic to human beings. The toxicity of hydrofluoric acid to human beings is further complicated by the fact that anhydrous hydrogen fluoride is typically a gas at normal atmospheric conditions of one atmosphere of pressure and 70° F. It is possible for the vapor pressure of hydrofluoric acid at standard atmospheric conditions to pose an inhalation risk if it is inadvertently exposed to the atmosphere. Although the safety record associated with most HF based alkylation units is very good, the potential exists for inadvertent release of HF into the atmosphere.
Due to the vapor pressure and corrosion associated with hydrofluoric acid, it would be beneficial to have an alkylation process using a catalyst composition, which would be an alternative to hydrofluoric acid. One possible alternative is the use of different liquid acids. However, other liquid acids can present corrosion and toxicity problems as well and tend to suffer rapid deactivation. This also requires the catalyst to be transported around a reactor/regenerator loop. Therefore, it would be desirable to have an alkylation catalyst composition that does not undergo rapid deactivation.